Method of matte or pyritic smelting.



- PATENTED MAY 19, 1903.

0. S. GARRETSON.

METHOD OF MATTHAND PYRITIG SMELTING.

APPLIOATION FILED FEB. 7, 1901. RENEWED 001210. 1902.

H0 MODEL.

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PATENT OFFICE.

OLIVER S. GARRE'I-SON, OF BUFFALO, NEW YORK, ASSIGNOR TO GARRETSON FURNACE COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF WEST VIRGINIA.

METHOD OF MATTE OR PYRITIC SMELTING.

SPECIFICATION forming part of Letters Patent N 0. 728,701, dated May 19, 1903.

Application filed February 7, 1901. Renewed October 10, 1902. Serial No. 126,803. (No specimens.)

To alt whom it may concern: 7

Be it known that I, OLIVER S. GARRETSON, a citizen of the United States, and a resident of Buffalo, in the county of Erie and State of New York, have invented a new and useful Improvement in Methods of Matte or Pyritic Smelting, of which the following is a specification.

This invention relates to the treatment of to matte by the converting or bessemerizing process in a blast-furnace underneath a column of ore and flux or silicious material. Operations of this character are described and claimed in Letters Patent of the United States, Nos. 596,991 and 596,992, granted to me January 11, 1898. In the process of Patent No. 596,991 the matte is converted or bessemerized in the same furnace in which it is produced from the ore by smelting. In the process of Patent No. 596,992 the matte is converted or bessemerized in a furnace which is separate from the smelting-furnace. When rich mattes are produced in this manner, the slag is correspondingly rich and carries off values which should be recovered in order to render the process economical and profitable.

The object of this invention is to conduct this treatment in such manner that rich matte of a uniform grade can be produced continu- 3o ously in the converting-furnace, and the resulting slag, which is'correspondingly rich, can be effectually cleaned and the values contained therein recovered by a simple and economical method.

The accompanying drawing represents in sectional elevation an apparatus by which my invention can be practiced.

A represents an upright converting or bessemerizing blast-furnace, in which matte is 40 produced by smelting suitable ores and the matte is converted or bessemerized to the desired degree of richness or concentration or in which matte which has been produced in I a separate furnace is converted. This furnace has its body composed, preferably, of a water jacketed column or stack of cylindrical, prismatic, or other suitable form and of any suitable construction. The furnace is preferably provided above its bottom b with a lower row of converting or bessemerizing twyers O and an upper row of smelting- [twyers D.

The converting-twyers C are arranged at such a height above the furnacebottom I) that they deliver the blast into the zone occupied by the molten matte below the slag-level. This converting-blast is injected under a sufliciently high pressure to enable the blast to penetrate the molten matte,which pressure may range from four to five pounds,

or more, per square inch. The upper row of smelting-twyers is arranged at the proper height above the bottom to deliver the blast for smelting the ore and flux, and the pressure of this blast is the usual low pressure for smelting, ranging from eight to sixteen ounces per square inch, or more.

In some cases the smelting-twyers may be omitted and the converting-blast made so large in volume that its excess which is not consumed in converting furnishes the smelt- 7o ing-blast.

'11. represents a tap-hole or spout arranged atone end of the furnace, at the bottom thereof, for drawing off the matte or metal, if the concentration is carried on to the point at which metal is precipitated.

F represents the slag-spout arranged at the opposite end of the furnace.

The top of the furnace is constructed in any suitable Orwell-known manner for introducing the ore and flux or silicious material and for directing the escape of the gases. This primary or converting furnace A is filled with a column of ore and flux or sili-- cious material in lumps. Quartz, diorite, or other mineral containing a large percentage of silica may be used for this purpose. The weight of this column keeps the lower portion of the column pressed down into the layer of matte, so that the iron oxid, which is formed in the matte by the oxidizing-blast, can come in contact with the silica and combine with the same to a silicate, which forms a liquid slag. The latter rises to the surface and escapes through the slag-spout, while the con- 5 centrated matte or the molten metal, as the case may be, escapes or is drawn 01f through the tap-hole E.

I represents a settling-well which receives the slag from the slag-spout of the furnace. This well is provided at convenient points with a slag-spout 2', through which the slag escapes from the well, and with a tap-hole k at the bottom of the well, through which any matte which may settle in the well is drawn off from time to time. This settling-well may,

however, be omitted in many cases. When a settling-well is used, the matte which is drawn oif from this well is returned to the converting-furnace A for treatment.

L represents a secondary blast-furnace which receives the slag by a spout Z from the settling-well or from the primary or converting furnace, as the case may be, and in which this slag is treated with sulfur-bearing ore for recovering the matte and other values contained in the slag. In its preferred construction this secondary furnace is used in part for converting or bessemerizing the matte and is provided only with a row of converting-twyers m, which deliver a blast of sufficient pressure and volume to operate not only upon the matte, but also upon the ore which is charged into the furnace.

n represents a tap-hole for drawing off the matte, arranged at or near that end of the furnace at which the slag enters the same, and 0 represents a slag-spout arranged at the opposite end of the furnace. The latter is provided at a suitable point between the taphole and the slag-spout with a transverse dam cious materialis mixed with the ore.

or bridgeP, which divides the furnace into a front compartmentp and a rear compartment 9 and which extends above the bottom q of the furnace to such a height that it confines the richer grade of matte to the front compartment, which lies nearest the tap-hole n.

The furnace L is charged with ore which is rich in sulfur. If necessary, some fiuxing materialsuch as quartz, diorite, or other sili- The sulfur, which is greatly in excess, reduces the metallic oxids and silicates contained in the slag tosulfids, thus forming a matte and cleaning the slag. The matte is treated in the front compartment in such a way that it is converted orconcentrated to the desired point-if desired, tothe precipitation of metalwhile the treatment in the rear compartment is carried on in such a way as to produce a low-grade matte, so that only practically clean slag is discharged from that compartment. The lowgrade matte which is produced in the rear compartment flows over the bridge intothe front compartment and replenishes the lat ter as the matte or metal is drawn off from the front compartment. The bridge is preferably formed by a transverse coil through which watercirculates and which is so mounted that it can be raised or lowered, as may be necessary, to adjust the top of the bridge to the height at which the desired flow of the matte takes place from the rear compartment to the front compartment. This height may diifer somewhat in different cases or at different times by reason of difference in the ores and other conditions. This bridge may,

however, be omitted, and the secondary or slag furnace L may be constructed in all respects like the primary or converting furnace A, or, if preferred, the slag-furnace L may be provided only with smelting-twyers and the converting-twyers may be omitted. In that case the resulting low-grade matte is returned to the, primary furnace for further concentration. This slag-furnace L is supplied with ore, which is rich in sulfur and with flux or silicious material, in the same way in which the converting-furnace A is supplied with ore. The sulfur contained in the ore and the poor matte produced from this ore combine readily with the values contained in the slag and the latter is thereby effectually cleaned. The cleaned or finished slag escapes through the slag-spout 0.

By cleaning the slag in a separate or secondary blast-furnace, as described, the expense of maintaining a fire in the slag-furnace is avoided, as the heat is maintained in the slag-furnace by the sulfur and other oxidizable ingredients of the ore, and both furnaces are operated in a very simple manner and in similar ways, whereby the operation is greatly simplified and the cost of labor, repair, and maintenance is considerably reduced. When only a converting-blast is used in the slag-furnace, the latter can be utilized at the same time for smelting concentrates, fines, flue-dust, and other material which cannot be successfully treated in an ordinary blast-furnace. Y

I claim as my invention- 1. The herein-described method of matte or pyritic smelting which consists in subjecting the molten matte to a converting or bessemerizing blastunderneath a column of material which contains a flux, removing the slag, and subjecting the slag to t he action of a blast underneath a column of sulfur-bearing material, substantially as set forth.

2. The herein-described method of matte or pyritic smelting which consists in subjecting the molten matte to a converting or bessemerizing blast underneath a column of material which contains a flux, removing the slag, separating the accompanying matte from the slag, and subjecting the slag to the action of a blast underneath a column of sulfur-bearing material, substantially as set forth.

3. The herein-described method of matte or pyritic smelting which consists in subjecting the molten matte to a converting or bessemerizing blast underneath a column of material which contains a flux, removing the slag, subjecting the slag to the action of a blast underneath a column of sulfur-bearing material, and subjecting the resulting molten matte to a converting or bessemerizing blast underneath a column of material which contains a flux, substantially as set forth.

Witness my hand this 28th day of January, 1901.

OLIVER S. GARRETSON.

Witnesses:

EDWARD WILHELM, CYESTA HORNBECK. 

